Short Film: The Schlieren Test

Red Dot Design Museum is built on the foundation of presenting and communicating good design in everyday products. In conjunction with the Exhibition: Mask Collection currently showing at the museum, Red Dot Design Museum Singapore presents The Schlieren Test, a short film that exemplifies the methods used by citizen scientists to test the efficacy of face masks in this pandemic. The pandemic has turned the layperson into a citizen scientist. Confined in their homes and with doubts cast on the mandatory mask-wearing practice, many learned to test the efficacy of life-saving PPEs—from surgical masks to home-made cotton masks—through basic experiments in their "home laboratory".

These product evaluation methods range from the simple flame test—where one attempts to extinguish a candle flame by blowing through one's mask—to the Schlieren imaging technique that requires a parabolic telescope mirror, a razor blade, a pinhole light source and a camera. Though rudimentary in their setup, these experiments visualise the airflow of our breath, coughs, sneezes and speech through face masks. By making the invisible tangible, these tests serve as a pertinent reminder of the importance of mask-wearing in a public health crisis.

An exploration of the Schlieren imaging technique on eight face masks of varied materials. From swimsuit nylon to home-sewn cotton, all eight face masks passed the candle flame test.

Though these experiments are not scientifically proven, they are visual reminders of the importance of good design, materials and the tools at our disposal to discern the quality of the products we use.

Supported by the Digital Project Grant of the National Heritage Board, Singapore.

Face Masks featured in this short film can also be purchased at the design museum shop.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Heritage Board, Singapore.